Various systems have been proposed to inform motorists of traffic hazards. Some systems use modulated carrier signals to convey traffic information. Others, such as described in U.S. Pat. No. 5,497,148 assigned to the assignee of the present invention, use unmodulated carrier signals to convey traffic information.
Regardless of the type of system used, a problem exists in that the traffic information being communicated may either become distorted or otherwise compromised by interference from nearby signals, such as police radar. The present invention is provided to solve this and other problems while at the same time simply accomplishing these objectives.